Frilled Sharks are elusive, deep sea sharks that were first observed on camera in their natural habitat back in 2004. Prior to that, they had only been seen after being caught in trawls (and even these was a very rare occurrences). Frilled Sharks can be found in oceans worldwide, though the distribution is patchy. The North Sea, areas around South Africa, and waters near Japan are some of the confirmed locations for the species. They live at depths of 500-1,000m, though are sometimes observed in shallower waters.

Frilled Sharks have some pretty interesting anatomy. They are so named because of the "frills" that cover their six gill slits on each side. They have very eel-like bodies, and mouths filled with 300 trident-shaped teeth arranged into 25 rows. It is believed that they strike at prey in a snakish manner, and around 60% of their diet consists of deep-sea squid.

Frilled Sharks also have some pretty remarkable reproductive habits. They are, like many sharks, ovoviviparous. The litter size is quite small, rarely numbering over 12, and at birth the offspring can be as large as 60cm. The really interesting thing is that some scientists believe that their gestation period lasts for 3.5 years. That is almost twice as long as an elephant's. If correct, the Frilled Shark has the longest gestation period of any vertebrate species.